Fall 2011 Classified as "Indian Summer"

The observed warm spell (Oct. 1-11) is often referred to as an "Indian Summer", which is generally associated with a period of much above normal temperatures and dry conditions after a killing frost/freeze. Looking back into September, International falls reached 19 degrees on September 15th with several other freezes since then. Duluth also froze on September 15th, reaching 30 degrees, with several other freezes since then.

October got off to an extremely warm start around the Northland. Several records were reached at both International Falls and Duluth as temperatures soared to above normal values. Precipitation was also hard to come by during this 11 day stretch. High pressure settled in to our east and the clockwise flow around the high created southerly winds which brought in warm air from the Southern U.S. This weather pattern was nearly stationary for the first 11 days of October. By October 12th, a strong low pressure system and associated cold front moved across the area, bringing an end to the extremely warm weather and sending temperatures back toward normal.

Duluth's average temperature was 11.7° above normal during the period of Oct. 1st-11th.

October 7 . . . 80° tied a record high temperature set in 1980

International Falls's average temperature was 14.7° above normal during the period of Oct. 1st-11th.

October 3 . . . 82° tied a record high temperature set in 1922
October 4 . . . 82° set a record high temperature (80° in 1912)
October 6 . . . 81° tied a record high temperature set in 1961
October 7 . . . 64° set a record warm low temperature (58 1909)

**Besides being the warmest low temperature for the date (Oct. 7), it is the warmest low temperature ever recorded for the month of October in recorded station history. The last time a daily low temperature of at least 64 degrees occurred so late in the season at International Falls was on September 30th, 1892 when the low was also 64 degrees.